Various methods are known and used for seaming woven industrial fabrics. These methods include several different methods of creating loops in yarns which would otherwise end at the end or edge of the fabric to be seamed, and connecting the loops of one end or edge to the opposing end or edge, either by inserting a coil through the loops to form a coil seam, or by interdigitating the loops to form a passage through which a pintle is inserted to form a pin seam. To create the loops, ends of selected yarns are conventionally woven back individually into the fabric to a sufficient distance to be secure, and may be further secured by stitching or other known means. These methods suffer from several disadvantages, including the time taken to perform the step of making the loops, and difficulties associated with ensuring sufficient seam strength, while at the same time maintaining compatibility of the characteristics of the fabric at the seam area and in the general fabric body.
It has now been found that it is possible to provide a pair of compatible seaming elements to a fabric, by attaching one of the pair of seaming elements to each of two opposing end regions or edges of a fabric to be seamed, in a simple, economical, and secure manner, such that when the end regions or edges are brought together, protrusions on the free outer edges of the pair of seaming elements can be attached to each other to form a secure seam, either by the connection of the protrusions per se, or by linking the protrusions in such manner as to provide a channel through which an additional seaming means such as a pintle can be inserted to secure the connection.
It has been found that the seaming elements can be attached by welding or other secure joining methods to the end regions of individual yarns of a woven fabric, or a fabric comprising yarns which are not interwoven, at the fabric end or edge to be seamed, either by securing selected yarns to outer surfaces of a seaming element, or securing selected yarns to inner surfaces within a seaming element, and that the seaming elements can be constructed in dimensions which are compatible with the overall fabric thickness so as to avoid or substantially minimize any difference in thickness at the seam area in comparison with the thickness of the fabric body.
Suitable protrusions can be provided either as single curved or angled protrusions from the free outer edge across the entire length of each seaming element, or as a set of individual channelled protrusions interspaced with notches or other spaces on each of a pair of the seaming elements, such that the sets can be interdigitated, and the channels through each protrusion aligned to define a single channel into which a pintle can be inserted and secured.
Further, it has been found that the seaming element can advantageously be constructed as an elongate body which can be provided either as a set of units interconnected at their lateral edges, or as a single integrally constructed body, in either case having a resultant length corresponding to the intended seam length.
It has further been found that the seaming elements can advantageously be used for non-woven fabrics which do not comprise yarns, such as fabrics comprising one or more layers of film.
The seaming element and method of the invention can be used for seaming woven and non-woven industrial fabrics of many types, particularly, but not restricted to, those used for filtration purposes. More particularly, the seaming element and method of the invention are especially suitable for use with woven papermakers' fabrics. In some respects, some of the features of the invention are discussed below in relation to its use for papermaking fabric applications; however, it will be understood that the invention is not restricted to use with such fabrics, but will be found useful in relation to any woven industrial fabric for which seaming in the general manner described below is feasible and advantageous.